Valve timing adjustment device

Abstract

A spiral spring ( 5 ) has an inner circumferential end ( 5 a ) fixed to a rotor ( 3 ) and an outer circumferential end ( 5 b ) fixed to a plate ( 8 ) of a housing ( 2 ), and biases the rotor ( 3 ) in one direction with respect to the housing ( 2 ). A projection ( 13 ) protrudes from the plate ( 8 ), and stops radially outward expansion of an outermost winding ( 5 c ) of the spiral spring ( 5 ). A clip ( 6 ) has a first portion ( 6 a ) coming in contact with the outermost winding ( 5 c ) of the spiral spring ( 5 ), and is attached to the projection ( 13 ) by elastic force of the clip ( 6 ).

The invention claimed is: 
     
       1. A valve timing adjustment device that adjusts opening and closing timing of an inlet valve or an outlet valve of an internal combustion engine, the valve timing adjustment device comprising:
 a first rotary body including hydraulic chambers; 
 a second rotary body having vanes each of which partitions a corresponding one of the hydraulic chambers into an advancing side and a retarding side, the second rotary body being rotatable relative to the first rotary body; 
 a spiral spring having one end fixed to the second rotary body and another end fixed to the first rotary body, the spiral spring being configured to bias the second rotary body in one direction with respect to the first rotary body; 
 a projection protruded from the first rotary body, the projection being configured to stop radially outward expansion of an outermost winding of the spiral spring; and 
 a clip having a first portion coming in contact with the outermost winding of the spiral spring, the clip being attached to the projection by an elastic force of the clip, wherein 
 the projection has a first wall face facing toward the outermost winding of the spiral spring, and a second wall face and a third wall face continuous with respective sides of the first wall face, an angle between the first wall face and the second wall face and an angle between the first wall face and the third wall face being acute angles, and 
 the clip has the first portion coming in contact with the outermost winding of the spiral spring, and a second portion and a third portion continuous with respective sides of the first portion, an angle between the first portion and the second portion being an acute angle smaller than the angle between the first wall face and the second wall face, an angle between the first portion and the third portion being an acute angle smaller than the angle between the first wall face and the third wall face. 
 
     
     
       2. The valve timing adjustment device according to  claim 1 , wherein the projection includes a retaining portion for preventing the clip from falling off. 
     
     
       3. The valve timing adjustment device according to  claim 2 , wherein the retaining portion includes a swaged portion of the projection. 
     
     
       4. A valve timing adjustment device that adjusts opening and closing timing of an inlet valve or an outlet valve of an internal combustion engine, the valve timing adjustment device comprising:
 a first rotary body including hydraulic chambers; 
 a second rotary body having vanes each of which partitions a corresponding one of the hydraulic chambers into an advancing side and a retarding side, the second rotary body being rotatable relative to the first rotary body; 
 a spiral spring having one end fixed to the second rotary body and another end fixed to the first rotary body, the spiral spring being configured to bias the second rotary body in one direction with respect to the first rotary body; 
 a projection protruded from the first rotary body, the projection being configured to stop radially outward expansion of an outermost winding of the spiral spring; and 
 a clip having a first portion coming in contact with the outermost winding of the spiral spring, the clip being attached to the projection by an elastic force of the clip, wherein the clip is made of a material of the clip is harder than the first rotary body and softer than the spiral spring. 
 
     
     
       5. The valve timing adjustment device according to  claim 4 , wherein the projection includes a retaining portion for preventing the clip from falling off. 
     
     
       6. The valve timing adjustment device according to  claim 5 , wherein the retaining portion includes a swaged portion of the projection. 
     
     
       7. A valve timing adjustment device that adjusts opening and closing timing of an inlet valve or an outlet valve of an internal combustion engine, the valve timing adjustment device comprising:
 a first rotary body including hydraulic chambers; 
 a second rotary body having vanes each of which partitions a corresponding one of the hydraulic chambers into an advancing side and a retarding side, the second rotary body being rotatable relative to the first rotary body; 
 a spiral spring having one end fixed to the second rotary body and another end fixed to the first rotary body, the spiral spring being configured to bias the second rotary body in one direction with respect to the first rotary body; 
 a projection protruded from the first rotary body, the projection being configured to stop radially outward expansion of an outermost winding of the spiral spring; and 
 a clip having a first portion coming in contact with the outermost winding of the spiral spring, the clip being attached to the projection by an elastic force of the clip, wherein the clip is made of stainless steel, the first rotary body is made of aluminum alloy, and the spiral spring is made of piano wire. 
 
     
     
       8. The valve timing adjustment device according to  claim 7 , wherein the projection includes a retaining portion for preventing the clip from falling off. 
     
     
       9. The valve timing adjustment device according to  claim 8 , wherein the retaining portion includes a swaged portion of the projection.